Process for making gas



Aug. 9 1938. A), R. STRYKER PROCESSFOR MAKING GAS Filed Sept. 30, 1935 2Sheets-Sheet 1 ATTORNEY.

CA HEg/A/g 7206? fies/1112s INVENTOR. HMEEf ,e {m /ls 9, 1938. -A. R.STRYKER 7 2,126,150

- PROCESS FOR MAKING GAS I Filed Sept. 30, 1935 2 Sheets-Sheet 2INVENTOR.

Patented Aug. 9, I938 PROCESS FUR PATENT OFFICE i l NG GAS Albert R.Stryker, Mariemont, Ohio, assignor of one-half to Chester Tietig,Covington, Ky.

Application September 30, 1935, Serial No. 42.7%

r Claims.

This invention relates to a process-for producing and reformingcombustible gases.

Among the objects of the invention are to provide a process for makingany gas of predetermined composition and heating valuefrom anycarbonaceous volatilizable and combustible material that is capable ofbeing very finely divided throughout a wide range of hydrogen content ofsuch gases.

One object is to provide a process for volatilizing hydrocarbonaceousmatter for reforming the resulting gas in the same apparatus.

Another object is to provide a process in which the rate and extent ofreformation of the gas is under exact control.

Another object is to provide a process in which the carbon produced byreformation of gas is deposited in an advantageous position for itsutilization in the further production of gas.

Another object is to provide a process for producing industrially purehydrogen from hydrocarbon raw material.

Another object is to utilize for such purposes certain low gradecarbonaceous materials which will be hereinafter mentioned and whichhave not heretofore been utilizable to produce gases of high heatingvalue or'high hydrogen content.

My apparatus is an improvement on, the'subject matter of my U. S. Patent1,855,034 and the improvement comprises means for obtaining partiallyor-completely reformed gases from various levels of the solid fuel bed,which levels can be easily selected.

Briefly stated, my process comprises passing finely dividedvolatilizable and/or combustible hydro-carbonaceous material thru ahighly heated zone then thru an incandescent bed of solid fuel andcracking the volatile constituents therein and then leading out the gasdesired from that level of the fuel bed at which it is formed.

Referring to the accompanying drawings, Fig. 1 is a somewhatdiagrammatic elevation, partly in section, of a producer-retortaccording to my invention, and the accessories necessary for itsoperation.

Fig. 2 is a horizontal cross section of the producer-retort along theline 2-2 of Fig. 1 and shows the walls of the fuel zone. V

Fig. 3 is a detail in vertical section of the producer-retort taken. onthe line 3-3, of Fig. 2.

Fig. 4 is a front elevation of one of the pierced refractory bricks usedat the fuelwzone for leading off the gas.

Referring again to Fig. 1, I0 is a retort shell which also serves as themain memberof a gas producer as well as a retort. Ill and itsaccessories are therefore hereinafter referred to as a. producer-retort.The shell in has preferably the high, double conical shape shown and inpractice may be 80 to 90 feet high and 11 feet in a diameter at itswidest zone tapering to about 4 feet in diameter at the top. Theinvention is not limited to such dimensions. The shell is supported bythree outside legs which are not shown. Support of this character leavesa free in space i l between the bottom of the shell and a fuel ll'l,preferably coal, is carried in the lower conical end up to the line 2-2,i. e., just under an air inlet it which is tangential to the shell. Atthe base of the shell there is a rotary eccentric grate iii, driven byan electric motor l6 and a scraper blade (not shown). The ashes whichfall into the space Ill are pushed over the rim of the circular wall I 2into an ash pit as the grate revolves. No novelty is claimed for therotary grate or ash handling arrangement per se.

Shell it is provided with a plurality of inclined ports it for chargingand maintaining the fuel bed. These are fed with coal from ahopper i9from which a branched delivery pipe 20 leads, and which ends in aplurality of dump gates 2!; From the latter charging buckets 22 can befilled and these can be dumped thru the ports it after 5 hydraulicallycontrolled valves 23 covering the ports, are opened. A control board 24is provided for operating these valves. Such fuel as is charged in thruports I8 for the purpose of establishing and maintaining the fuel bed,is hereinafter called maintenance fuel.

At the top of shell II! is a port 25. thru which solid fuel intendedto-operate the gas making process is charged. Such fuel may be anythingof a hydrocarbonaceous nature and need not be 5 solid. If it is liquidit is charged in thru pipe 26; if it is gaseous thru pipe 21. One ormore kinds of fuel can be here introduced together or intermittently orsingly. The fuel introduced at the top of the retort for operating theprocess, I call operating fuel.

At the upper left side of Fig. 1 there is shown a coal powdering plant28 which is conventional.

It has a delivery hopper 29 for coal dust'which dust is transferred tothe producer-retort by 557 means of screw'conveyor 30. 3| is a motordriven spreader drive. As the dust falls it encounter revolving spreader32 which can also serve as a valve to close port 25 when desired. 'Belowthe top of shell ll] there is an ofitake 33 which runs thru a waste heatboiler 34 having a steam drum 35 and a steam delivery pipe 36 in whichthere is a diaphragm regulating valve 31, said pipe carrying steam to aturbine 61. Offtake 33 runs to a wash box 39 having an outwardly openinghydraulically operated flap valve 40, a gas delivery pipe 4i and a waterreplenishing and dust disposal system 42. Suitable valves 43 may bearranged in the gas delivery pipe. 7

In the offtake 33 between the. top of shell l0 and waste heat boiler 34,there is a hot valve 44, i. e., a valve adapted to operate at hightemperatures. It is controlled by a. hydraulic cylinder and piston 45and its function is to close off the ofitake 33 during the gas makingstep of .the

process. I

About the shell in at the upper part of the zone of maintenance fuelthere is a plurality of circular manifolds 43. Each of these connects toa downcoming manifold 41 and each circular manifold may be shut off fromthe latter by a valve 48. Each circular manifold taps the shell in atfour equidistant points. The circular manifolds may be of any selectednumber, but each is at a different level and connects by means of ashort extension 49 to a gas channel 53 which is within the shell ill ata point below the top of the fuel bed. The inner wall of channel 50 isdefined by a circular row or rows of the pierced refractory brick 5|,preferably of silicon carbide, one of. which is shown in front elevationin Fig. 4 and several in section in Fig. 3 and in plan in Fig. 2.

Each brick or block 5| is provided with three rows of three transverseholes 52. The holes communicate with a longitudinal channel 53 whichextends along the rear of the block, this channel constituting a meanswhereby the gas from the holes 52 may be collected into a single stream.In my apparatus channel 50 may be identical with channel 53 or it may beand preferably is a channel additional thereto but in free communicationtherewith at all points. Suitable dividing blocks 54 are shown which mayalso be employed to support the brickwork from the shell l0 and thesesupports may be of any suitable form. The brickwork is however providedwith tongues 55 and grooves 56 which contribute to its stability.

The depth of the gas oiftakes below the level of the fuel bed is ofimportance. If a bed of .maintenance fuel of 9 to 11 feet deep is used,

the topofitake, .i. e., the top rows of pierced brick should be from 2to 3 feet below the top of the fuel bed, the second from 3 to 5 feetbelow and the third from 5 to 7 feet below.

Beneath the grate l5 there is a generally conical inverted bell 51 intowhich an. airdelivery pipe 58 from a blower 53 and a gas exit pipe 50are fitted. There is also a steam supply pipe 6| fitted into the exitend of the air pipe 58. The latter pipe has a branch 62 which connectswith the tangential air inlet l4 above the fuel bed. Both air pipes areprovided with shutoff valves 33 and 84 respectively and butterflies 35and 63 respectively.

A steam'supply pipe I2 having a valve 13 is arranged nearthe top ofshell III for a. purpose later to be described.

While my process may be carried out in other apparatus, when it isexecuted in that shown the operation is as follows: 7

Lump fuel, preferably coal, but permisslbly coke is first charged intothe producer-retort and ignited. The degree of subdivision of this fuelshould be between pea x A") and furnace lump (4" x 6").

After ignition the air blast is turned on from pipes 58 and 62 and thecharging process is continued until the fuel bed reaches the desiredlevel, which is thereafter maintained. Secondary air fed in throughtangential opening I4 is limited in amount so as to be only sufficientto burn the CO above the fuel bed to CO2. Heating is thus continueduntil the producer retort above the fuel bed is heated at least in partto about 1400 F. plus 400 or minus 100. During this operation valves 44and 40 are open permitting smoke to be vented off thru a stack 12without going thru the water in the wash box. As soon as ash formationor clinker formation begins electric motor I6 is started, therebyrotating eccentric grate l5 so as to catch and crush clinkers betweenthe grate and the shell H]. The scraper blade (not shown) transfers ashfrom the space between the ring l3 and the shell 80 to an annular ashpit surrounding same.

Enough steam has now accumulated in waste heat boiler 34 to operateexhauster 61 thru its turbine until the next blow" or healing period. Ifthe quantity of steam should be insufficient auxiliary energy may besupplied from without the system. Exhauster 61 is now started, blower 53stopped, valves 63, 54 and 44 closed, thereby automatically closingvalve 40 and all valves in the gas discharge lines 41, 6B and 4! areopened;

those in' the latter line at least to some considerable extent.

Finely divided operating fuel is now fed from conveyor 33, thru opening25 into the top of the producer-retort and allowed to fall as freely asit may but still under influence of the suction created by exhauster 61,to the top of the fuel bed. Carbonizatlon and liberation of gas takesplace during the descent and after the particles have come to rest onthe surface of the fuel bed or in its interstices. Charging of operatingfuel is so conducted that a minimum of air is ad-, mitted with the fuel,i. e., the sealing and revolving spreading bell 32 is raised to a pointthat will allow continuous .dropping into the producer-retort of thedesired amount of fuel with little or no air.

Gas delivery pipe 80 runs to a steam-turbine driven exhauster 61 andbefore it reaches the latter, it is joined by'gas delivery pipe 41 fromthe manifolds 43. From the exhauster pipe extends to the wash box 39.

Steam for driving the exhauster 61 is supplied from the steam drum 35ofwaste-heat boiler 34 thru a pipe 68in which there is a.diaphragmcontrolled spring loaded regulating valve 31 shown inexaggerated size on Fig. 1. This valve is conventional and may be eitherthe one sold by the Chaplin-Fulton Mfg. Co. of- Pittsburgh,

Pa., under the name of "Duplex Steam Control for Gas'Producers or thatmade by the' Fisher Governor Co.' .o'f Marshalltown, Iowa. as Type 1560,"Low' Pressure Diaphragm Actuated Valve."

. From the diaphragm chamber 10 of valve 31 a pressure-communicationpipe 'Il ms to the interlor of shell ID to a point just above the fuelbed. The valve 31 is so arranged that the interior of shell I. shallmaintain as closely as posorator,

in pipe M.

Bible 11. minus pressure of 0.2 inch of water. This value may be variedat the will of the op but is recommended for ordinary operation. Thevalve regulates the steam supply to the exhauster turbine so that if thepressure in.

shell Ill rises to an undesired value, more steam will be admitted tothe turbine, the exhauster will increase its speed and consequentlylower the pressure within the shell Ill.

The level of the fuel bed from which the gas is to be taken is selectedby opening the valves W at the levels desired to withdraw gas thruopening a valve '83 in line 6t. Any desired blend of gas may be made byregulating valves 48 or it and if desired also by the use of a valve 74The lower the, level selected, the

,higher will be the hydrogen content of the gas and ii the entire depthof bed is utilized bywithdrawing gas exclusively from the bell 51,industrially pure hydrogen will be the product. In any case the gasoutput passes thru a portion of pipe of being finely divided to it belowthe exhauster and the remainder of said pipe above the exhauster to bewashed in wash box M and to make its exit from pipe ti.

The operating fuel may be any kind of coal, anthracite, bituminous,lignite, mine refuse and off season stocks. It may also be petroleum oilor its fractions including fuel oil, gas oil, still bottoms, gasoline,kerosene, butane, ethylene and others. Natural gas and refinery gas maybe used since, while these substances undergo a diminu tion oil heatingvalue when put thru my process. they also undergo a considerablepermanent expansion in volume. Wood fiber, straw, corn stalks, cocoanut,cottonseed oil, animal fats, fatty acids, residues from fatty aciddistillation, spoiled fats and any hydrocarbonaceous material capableprticles of say square or smaller, can be used. The termhydrocarbonaceous as I use it includes fatty carbohydrates.

If freedom from by-products (tars, light oil, etc.) which might clogcity gas lines, is desired the lower level of the fuel bed should beselected as the source of the gas. The lower the level selected,however, the lower will be the heating value of the gas obtained, thegreater the freedom from lay-products, the higher the hydrogen contentand the greater the permanent gas vol ume.

For the production of city gas, of highest heating value, the preferredmethod would be to take gas only from the top ofitake. fairly lowheating value but carrying little or no lay-products, gas from themiddle or lower side oiltakes'is to be chosen. For the production of allhydrogen for process work or for mixing with other gases fortransportation, the offtake below the grate is to be selected.

In the case of reformation ofgaseous fuels, with a temperature of 1500F. at first or top olftake a 65GB. t. u. coal gas may be cracked back.to 600 B. t."u.

With the same temperature at first offtake and 1700 F. at the second, a650 B. t. u. gas may be cracked back to 500 B. t. u.

With the above temperatures at the first two oil'takes and 2000 F.(partially in the incandes-.

u. gas may be torn oiftake, the gas may be completely cracked toapproximately 325 B. t. u. which is an indi- For a gas of cation of itsnearly pure hydrogen composition.

,, air fed to the producer-retort both above and the holes and channelsin the pierced bricks or below the fuel bed. The tangential inclinationof port I 4 causes the air to have a scurilng action on the walls of theretort and thus any carbon clinging to the retort walls is efiicientiyburned. The hot gases produced by the combustion find their exit thruthe ofitake or leading off means 33 and in doing so heat the waterin'wasteheat boiler 34 and so to wash box 39. Here, because the gasesare under considerable pressure hydraulically operated valve til openswith accompanying smoke and stack 12.

dust, pass up the A number of common and well known types andcombinations of types of gases may be produced in addition to the gaseshereinbefore mentioned. The producer portion of the apparatus may makeeither air blown or steam producer gas independent of or in combinationwith partially:

.steam may-be admitted to the upper portion of the retort through seamconnection '12 passing downwardly through the fuel bed and leaving thegas ofitake below the grate and allowed to flow under its own pressurethrough exhauster bl and into pipe lill to the washbox.

Oil gas may also be produced by spraying oil into the upper reaches ofthe heated retort through pipe 26. With hot valve M open and all otherconnections closed the oil gas thus proand the gases ill) duced mustpass through the washbox under its 7 own pressure.

Oil gas can further be produced and utilized to carburet or enrichproducer gas or blue gas before described.

It is evident that if any of the gases described or any combination ofgases described can be utilized either separately or in combination withthe process of cracking hydrocarbon-gas that carbon deposited in thefuel bed due to cracking and also residues from solid operating fuelsmay be utilized for the production of gas or merely for the heating ofthe retort.

Due to the fact that secondary air blast connection I4 is tangential tothe shell of the retort and a swirling motion is imparted to the air itis possible to properly manipulate butterfly valves and 65 (afterignition is attained above thefuel bed) to pick up solid residuedeposited on the top of the fuel bed after a gas run and burn the finelydivided fuel within the retort much the same as firing a boiler withpowdered fuel. The

products of combustion and ash leave through the oiftake 33 and arevented to the air through stack 12.

I claim as my invention:

1. That step in the process of making a combustible mixture of gasescomprising free hydrogen which comprises dropping finely divided solidhydrocarbonaceous matter thru a space hot enough and deep enough tovolatilize substantially all of the gas producible by the pyrolysis ofsaid matter and withdrawing the gas so produced from a selected level ofa fuel bed maintained at least in part at incandescence at the bottom ofsaid space from a region below the upper surface of said bed.

'2. That step in the process of making a combustible mixture of gasescomprising free hydrogen which comprises dropping finely dividedhydrocarbonaceous fuel thru a space hot enough and long enough tovolatilize substantially all of the volatile constituents thereof whichcan be freed by the pyrolysis of the said fuel, maintaining a bed ofoperating fuel at least in part at incandescence at the lower end ofsaid space and withdrawing the said gas from a region below the top ofsaid fuel bed from the sides thereof also, simultaneously, from belowthe bottom of said fuel bed and mingling the two currents of gas sowithdrawn.

3. The process of cracking gas which comprises directing a stream ofhydrocarbonaceous crackable .gas downward thru a bed of fuel hot. enoughto crack said gas and deep enough and composed of particles fine enoughto retain most of the carbon generated by the reaction and then removinggas which has been cracked to the extent desired from a selected leveland from the sides of said fuel bed, while preventing further contact ofthe gas with the fuel bed during the step of removal.

- that withdrawn from the other regions.

5. The process which comprises dropping thru a pyrolyzing zone a finelydivided hydro-carbonaceous solid fuel onto a bed of lump fuel at leastpartially at incandescence, said bed being composed of particles notsmaller than pea size coal and. not larger than lump coal, the bed beingadapted to retain the greater part of the solid residues of cracking ofsaid finely divided fuel within the interstices of the bed, and thenwithdrawing from a selected region in said bed a stream of gaseousproducts of pyrolysis at a low velocity from the sides of said bed.

- 6. A process according to claim 5 in which the operations of gasgeneration and withdrawal are conducted at a pressure slightly belowatmospheric. I

'7. That step in the process of making a mixture of gases comprisingfree hydrogen, which comprises dropping finely divided hydrocarbonaceousfuel thru a space hot enough and long enough to volatilize substantiallyall of the volatile constituents thereof which can be freed by thepyrolysis of the said fuel, maintaining a bed of operating fuel at leastin part at incandescence at the lower end of said space and withdrawingthe said gas from a region below the top of said fuel bed from the sidesthereof.

ALBERT R. STRYKER.

